The present invention relates to a method and apparatus for polishing a workpiece by electrical discharges by means of an electrode tool, for achieving a smooth surface finish on the workpiece.
It is known, in electrical discharge machining, to effectuate consecutive finishing passes by displacing the workpiece and electrode tool according to a relative cyclical translation motion in a plane perpendicular to the direction of feed of the electrode tool into the workpiece, the finishing passes being effected with electrical discharges of progressively decreasing intensity. The quality of the finished surface thus obtained has a limit which does not always correspond to industrial requirements, more particularly for obtaining a surface having craters of less than 0.1 microns in average value.
A process is known for polishing, by electrical discharge machining, a workpiece electrode by means of an electrode tool, wherein the electrodes are displaced according to a relative cyclical motion of translation at a predetermined amplitude, while supplying across the electrodes consecutive electrical discharges of a predetermined intensity, the amplitude of the translation motion being chosen as a function of the decrease of dimensions of the electrode tool relative to that of the surfaces to be polished.